Lyman Continuum Extinction by Dust in H [CSC]ii[/CSC] Regions of Galaxies

Inoue, Akio

doi:10.1086/323095

Cited by 84 publications

(96 citation statements)

References 45 publications

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“…For ρ ∝ 1/r; for 1/r 2 the mass is 30% less. f Lyman continuum rate from the literature, primarily (Turner et al 1998;Bendo et al 2017), and corrected for 30% direct absorption of uv photons by dust (Turner et al 2015) following the procedure of Inoue (2001). Corrected to 3.8 Mpc.…”

Section: Cloud D1 and The Supernebulamentioning

confidence: 99%

ALMA Detects CO(3–2) within a Super Star Cluster in NGC 5253

Turner

Consiglio

Beck

et al. 2017

ApJ

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We present observations of CO(3-2) and 13 CO(3-2) emission near the supernebula in the dwarf galaxy NGC 5253, which contains one of the best examples of a potential globular cluster in formation. The 0. 3 resolution images reveal an unusual molecular cloud, "Cloud D1", coincident with the radio-infrared supernebula. The ∼ 6-pc diameter cloud has a linewidth, ∆v = 21.7 km s −1 , that reflects only the gravitational potential of the star cluster residing within it. The corresponding virial mass is 2.5 × 10 5 M . The cluster appears to have a top-heavy initial mass function, with M * 1-2 M . Cloud D1 is optically thin in CO(3-2) probably because the gas is hot. Molecular gas mass is very uncertain but constitutes < 35% of the dynamical mass within the cloud boundaries. In spite of the presence of an estimated ∼ 1500 − 2000 O stars within the small cloud, the CO appears relatively undisturbed. We propose that Cloud D1 consists of molecular clumps or cores, possibly star-forming, orbiting with more evolved stars in the core of the giant cluster.

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Section: Cloud D1 and The Supernebulamentioning

confidence: 99%

ALMA Detects CO(3–2) within a Super Star Cluster in NGC 5253

Turner

Consiglio

Beck

et al. 2017

ApJ

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“…We note that L young unit, ion−uv is not included in the definition of L young unit . 6 The fraction of ionising UV photons that is absorbed by dust in HII regions exhibits a broad range of values, varying from 0.3−0.7 Inoue 2001). However, even if this fraction approaches unity, their contribution to the dust emission of the starforming complexes is still only at the percent level, because the intrinsic luminosity of the ionising UV photons is so much smaller than that of the non-ionising UV photons (Bruzual & Charlot 1993).…”

Section: The Template Sed Of the Old Stellar Population In The Bulgementioning

confidence: 99%

Modelling the spectral energy distribution of galaxies

Popescu

Tuffs

Dopita

et al. 2011

A&A

207

454

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We present a self-consistent model of the spectral energy distributions (SEDs) of spiral galaxies from the ultraviolet (UV) to the mid-infrared (MIR)/far-infrared (FIR)/submillimeter (submm) based on a full radiative transfer calculation of the propagation of starlight in galaxy disks. This model predicts not only the total integrated energy absorbed in the UV/optical and re-emitted in the infrared/submm, but also the colours of the dust emission based on an explicit calculation of the strength and colour of the UV/optical radiation fields heating the dust, and incorporating a full calculation of the stochastic heating of small dust grains and PAH molecules. The geometry of the translucent components of the model is empirically constrained using the results from the radiation transfer analysis of Xilouris et al. on spirals in the middle range of the Hubble sequence, while the geometry of the optically thick components is constrained from physical considerations with a posteriori checks of the model predictions with observational data. Following the observational constraints, the model has both a distribution of diffuse dust associated with the old and young disk stellar populations as well as a clumpy component arising from dust in the parent molecular clouds in star forming regions. In accordance with the fragmented nature of dense molecular gas in typical star-forming regions, UV light from massive stars is allowed to either freely stream away into the diffuse medium in some fraction of directions or be geometrically blocked and locally absorbed in clumps. These geometrical constraints enable the dust emission to be predicted in terms of a minimum set of free parameters: the central face-on dust opacity in the B-band τ f B , a clumpiness factor F for the star-forming regions, the star-formation rate SFR, the normalised luminosity of the old stellar population old and the bulge-to-disk ratio B/D. We show that these parameters are almost orthogonal in their predicted effect on the colours of the dust/PAH emission. In most practical applications B/D will actually not be a free parameter but (together with the angular size θ gal and inclination i of the disk) act as a constraint derived from morphological decomposition of higher resolution optical images. This also extends the range of applicability of the model along the Hubble sequence. We further show that the dependence of the dust emission SED on the colour of the stellar photon field depends primarily on the ratio between the luminosities of the young and old stellar populations (as specified by the parameters SFR and old) rather than on the detailed colour of the emissions from either of these populations. The model is thereby independent of a priori assumptions of the detailed mathematical form of the dependence of SFR on time, allowing UV/optical SEDs to be dereddened without recourse to population synthesis models. Utilising these findings, we show how the predictive power of radiative transfer calculations can be combined with measurements of θ ...

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“…Measurements of the fraction of emerging flux f ion for individual H II regions indicate that it can vary substantially, with a range of   f 0.2 1.0 ion within local galaxies (Inoue 2001;Inoue et al 2001). However, galaxy-wide averages for local spiral galaxies (MW, M31, M33) suggest a typical value off 0.4 ion (Inoue 2001). Given that the galaxies selected for this analysis correspond to active star-forming systems (which are preferentially disk galaxies), we adopt = f 0.4 ion as a reasonable choice moving forward.…”

Section: Uv Nir Int Obsmentioning

confidence: 99%

“…For this analysis, we use their model based on 20% of carbon atoms locked up in PAHs. The ionization parameter is determined using the relationship from Kobulnicky & Kewley (2004, their Equation (13) , corresponding to a lower direct dust absorption, than the galaxy-wide averages found in Inoue (2001). It can be seen in Figure 9 that differences in the appropriate values for these attenuation variables for individual galaxies could give rise to the observed scatter.…”

Section: Uv Nir Int Obsmentioning

confidence: 99%

Characterizing Dust Attenuation in Local Star-forming Galaxies: Near-infrared Reddening and Normalization

Battisti

Calzetti

Chary

2017

ApJ

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We characterize the near-infrared dust attenuation for a sample of ∼5500 local (  z 0.1) star-forming galaxies and obtain an estimate of their average total-to-selective attenuation l ( ) k . We utilize data from the United Kingdom Infrared Telescope and the Two-Micron All Sky Survey, which is combined with previously measured UV-optical data for these galaxies. The average attenuation curve is slightly lower in the far-ultraviolet than in local starburst galaxies by roughly 15% but appears similar at longer wavelengths with a total-to-selective normalization of = -+ R 3.670.44 . Under the assumption of energy balance, the total attenuated energy inferred from this curve is found to be broadly consistent with the observed infrared dust emission (L TIR ) in a small sample of local galaxies for which far-infrared measurements are available. However, the significant scatter in this quantity among the sample may reflect large variations in the attenuation properties of individual galaxies. We also derive the attenuation curve for subpopulations of the main sample, separated according to mean stellar population age (via D 4000 n ), specific star formation rate, stellar mass, and metallicity, and find that they show only tentative trends with low significance, at least over the range that is probed by our sample. These results indicate that a single curve is reasonable for applications seeking to broadly characterize large samples of galaxies in the local universe, while applications to individual galaxies would yield large uncertainties and is not recommended.

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Lyman Continuum Extinction by Dust in H [CSC]ii[/CSC] Regions of Galaxies

Cited by 84 publications

References 45 publications

ALMA Detects CO(3–2) within a Super Star Cluster in NGC 5253

ALMA Detects CO(3–2) within a Super Star Cluster in NGC 5253

Modelling the spectral energy distribution of galaxies

Characterizing Dust Attenuation in Local Star-forming Galaxies: Near-infrared Reddening and Normalization

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